Steam-air inhalator

ABSTRACT

A steam and air mixing chamber having a downwardly open housing is mounted on top of a steam generator located in a housing containing a water reservoir. A steam nozzle directs a jet of steam against a baffle mounted in the mixing chamber entraining air and forming a mist. Compressed air is directed into the mixing chamber by a venturi tube, thereby sucking in the mist and causing the mixture to flow into a breathing element. The vacuum and thus the vapor and mist temperature, are controlled by a shielding means which can be moved to overshadow a portion of venturi tube orifice, thereby diverting some of the airstream leaving the venturi tube.

FIELD OF THE INVENTION

This invention relates to a steam-air inhalator device for convertingwater vapor to a fine mist, to be used, for example, to supply moist airor oxygen to a patient for breathing purposes, and more particularly toa means for controlling the temperature of the moist air and oxygen.

BACKGROUND OF THE INVENTION

Nebulizers are known in which preheated water is driven in a thin streamagainst a target so as to break up into small particles which mix withthe surrounding air in order to moisturize same. Other systems useultrasonic vibrations to fragmentize the water stream. It is generallydesired to make the particle size as small as possible, preferably of 5microns or less, so as to facilitate penetration of the water particlesinto the respiratory tract of a patient. However, the mist produced inthis manner is not very stable since the water particles are notuniformly dispersed in the airflow and tend to coalesce, thereby forminglarger droplets which settle out prematurely in the supply conduit aswell as in the respiratory tract itself. The equipment is relativelyinefficient, complex and correspondingly expensive, especially for homeuse; moreover, unless the water is preboiled, sterile conditions aredifficult to maintain.

In U.S. Pat. No. 3,894,537, I have described an effective steam-airinhalator which gives very satisfactory results. My copendingapplication Ser. No. 868,569 filed Jan. 10, 1978 is an improvement overthis patent in that provision is made for incorporating medication inmoist air, or oxygen, or oxygen-rich air and also for returningcondensate to the steam generator. Both said patent and application areincorporated herein by reference.

It is a general object of this invention to provide an improvedinhalator for producing a stable mist of submicron particles wherein thetemperature of said mist can be varied.

A further object is to provide a means to vary the direction of aportion of a pressurized gas stream exiting a venturi tube to vary thevacuum produced in a venturi.

SUMMARY OF THE INVENTION

I realize these objects, in accordance with my present invention, byproviding a mixing chamber whose housing has an internal channel partlyobstructed by a generally transverse baffle, the housing having anentrance for ambient air communicating with the channel in the vicinityof the baffle. A channel inlet on one side of the baffle has means fordirecting a jet of stream against the baffle whereby steam in deflectedinto the surrounding air to form a mist. The surrounding air isconstantly aspirated from the ambient atmosphere through theaforementioned entrance with the aid of suction means communicating withthe channel on the opposite side of the baffle. An outlet fordischarging the mist-laden aspirated air from the channel is provided.

The housing is open at its underside, forming a channel, and the nozzledirects a jet of steam against a baffle located within the channel.Ambient air is drawn into the channel and a superfine mist is formed. Atthe end of the channel a venturi fitting is located and compressed air,oxygen, or enriched air is passed through a venturi tube. The mist plusadditional air is thereby forced into a T connection having a lateralarm attached to a breathing mask or a mouth piece. By laterallydeflecting a portion of the gas stream leaving the venturi tube thedegree of vacuum created can be changed. As a result, the temperature ofthe mist entering the breathing mask or mouth piece will likewise changesince a higher vacuum will draw more steam-air mixture into the venturiand vice-versa. Means are provided to control the venturi gas streamthereby permitting vapor temperature control by the user.

Copending application Ser. No. 868,569 shows a carrier having volatilemedicament thereon which may be inserted through a port in the Tconnection whereby the mist can be medicated, as for example withantibacterial and decongestant agents. One end of the T connection canextend into the water in the reservoir and serve as a condensate returntube.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is an elevational view with parts in section of the inhalatorapparatus according to my invention.

FIG. 2 is a perspective view of the inhalator.

FIG. 3 is a sectional view of the inhalator.

FIGS. 4 and 5 are sections along lines 4--4 and 5--5 in FIG. 2.

FIG. 6 shows a face mask connected to the inhalator.

FIG. 7 shows a mouth piece for connection to the inhalator.

FIG. 8 is a sectional view of the venturi.

The apparatus shown in FIG. 1 comprises a vaporizer having a top surface2, only a portion of the vaporizer being shown. Advantageously this hasthe construction of the steam generator disclosed in my prior U.S. Pat.No. 3,743,780. A boiling unit 3 having a top surface 4 and a pair ofelectrodes encased therein, fits into a raised opening 5 in the topsurface of the vaporizer. Steam nozzle 6, which is integrally formedwith the top surface 4, has a passageway 7 connected with the boiler forthe passage of steam generated therein, and an orifice 8.

A steam-air mixing chamber 9 has a housing 10 with an internal channel11 open at the bottom. This channel is partially obstructed by atransverse baffle 12 depending from the closed top of the housing.Depending lugs 12a on the bottom of the housing are adapted to fit intoa notch 13 in the top surface of the boiling unit and aids in retainingthe mixing chamber in place. One end of the housing 10 is generallycylindrical as shown at 14 having as shown in FIGS. 3 and 5 an internalbore 14a adapted to receive the steam nozzle 6. Bore 14a has a slot 15in line with orifice 8 in the nozzle. To retain mixing chamber 9 on thevaporizer, screw 16 passes through the mixing chamber at its uppersurface at 14 into the top of steam nozzle 6. The end of the mixingchamber opposite 14 likewise is generally cylindrical as shown in FIG. 2at 17 with a bore 18 having vertical slot 19 therein. Slots 15 and 19are in line with channel 11, so that a passageway is formed from steamnozzle 6 through passageway 7, orifice 8, slot 15, channel 11, slot 19and bore 18. Mounted in the upper end of 17 and concentric therewith isverturi tube 20. Pressurized gas, such as for example air, oxygen,oxygen-enriched air, or other gas is passed through 20 into bore 18. Itwill be seen from FIG. 3 that baffle 12 terminates above the top surfaceof boiling unit 3 so as to leave free a passage through which ambientair can be aspirated by the steam flowing around the baffle.

Mist laden air from channel 11 with additional ambient air enteringthrough an opening 21 in the top of housing 10 near cylindrical end 17,are aspirated into bore 18 through slot 19 therein. Fitting overcylindrical end 17 at the lower end is a connection consisting of tube22 having a lateral arm 23, forming a T. Above arm 23, in tube 22 is aport 24 adapted to receive a carrier, such as a rod 25 which is coatedwith a volatile medicament which can vaporize in the warm stream of mistflowing past it. Various antibacterial and decongestant agents may beemployed for use of the invention in treating respiratory ailments, asfor example a mixture of camphor, menthol and petrolatum. Rod 25 iscoated with a pre-measured dosage by merely dipping the rod into themedicament, which is in the form of a jelly.

The lower end 26 of tube 22 extends through top surface 2 below thelevel of water in the reservoir and serves to return condensate thereto.Attached to the side arm 23 is flexible tube 27 attached to aconventional face mask 28, (FIG. 6) or to a mouth piece 29 (FIG. 7).

The amount of steam evolving from the generator and the flow rate ofpressurized gas should be so chosen as to let the mixture of superfinemist and gas to arrive at the face mask or mouth piece at about bodytemperature, i.e. approximately 37° C. By way of example and without anyintention to limit the invention to the following parameters, I havefound that air delivered to the venturi tube 20 at about 2 psi and 200cu. in. per minute is satisfactory.

The amount of steam entering the breathing element as well as thetemperature of the mixture of gas and mist entering side arm 23 may beraised or lowered by reducing or enlarging the size of the channel andaccordingly, thereby lower or raise the temperature. Variation of thesteam flow may likewise be accomplished by changing the depth of baffle12. A shallower baffle would allow more steam to pass and thus increasethe temperature, while the converse would hold with a longer baffle.Altering the size of opening 21 to vary the amount of ambient airentering the channel through said opening would likewise serve tocontrol the temperature; an increase in the diameter would admit moreambient air and hence lower the temperature, and vice versa.

Returning any condensate formed to the water reservoir enables vaporizerto be used for periods as long as eight hours or more without refilling.In addition, removal of the condensate before it enters the breathingelement avoids exposing the patient to the discomfort of havingcondensate dripping on his body and clothing, so that a long exposuretime can be comfortably tolerated.

A preferred method for varying the temperature of the mixture of gas andmist is by partially deflecting the flow of pressurized gas as it leavesthe venturi from its normal flow path thereby changing the vacuumproduced. The higher the vacuum, the more steam will enter the interiorof cylindrical end 17 and conversely. The quantity of compressed gasentering and leaving 17 is not varied, only the direction of flow of aportion is altered at the venturi nozzle, as dscribed below. As aresult, the temperature of the mist leaving 17 and entering thebreathing apparatus can be readily controlled.

As best shown in FIG. 8, a valve 30 having smooth stem portion 31, aflat end portion 32 and a threaded portion 33, a head 34 and gripper 35passes through a threaded opening in the wall of 17. The rotation ofvalve 30 is limited by a pin 36, fastened to 34 as shown, which isadapted to abut a stop 37 in the outer wall portion of 17.

As a result of the pin and stop, the valve can rotate no more thanslightly less than one complete revolution. Venturi 20 has a nozzleopening 38 and when the valve is in its furthest extended position asshown in FIG. 8, end 32 is at the midaxis of opening 38. The threadpitch at 33 is such that the retracted position end 32 clears theopening completely. The vertical distance between 32 and 38 is small,but the valve stem does not touch the venturi tube. If desired the end32 may extend beyond the midaxis of 38 and even go beyond thecircumference of the opening in the extended position of 30. However, inthis case the pitch of the thread must be such that the retractedposition of stem 31 will fully clear opening 38. In the wall of 17generally opposite 30 is hole 39 which serves to admit additionalambient air into the chamber of cylindrical end 17. It will beappreciated that in all settings of stem 31 the quantity of gas enteringthe chamber through the venturi tube 20 will be essentially the same.

When the compressed gas stream leaving the orifice is deflected by thestem 31 and stop pin 36 is in contact with boss 37 so that the stem isin its maximum extended position, the vacuum is at its minimum and theinhalator is at its coolest operating condition. Contrariwise, when thestem is at its minimum extended position with stop pin 37 contacting theopposite side of boss 37 the venturi opening is unobstructed and themaximum vacuum is generated. In this position the inhalator is at itswarmest operating setting, other conditions being equal.

While the control means for the venturi has been described in connectionwith the apparatus set forth in my copending application Ser. No.868,569, it is equally efficacious in the venturi fitting described inmy prior U.S. Pat. No. 3,894,537. In general the method described hereinfor controlling the vacuum of a venturi by a partial direction of thehigh pressure gas is applicable to venturis as a class.

What is claimed:
 1. In a vaporizer comprising a water reservoir, a steamgenerating means having a steam outlet nozzle and connected to saidreservoir, a steam-air mixing chamber in communication with ambient air,the said outlet nozzle connected to one end of said steam-air mixingchamber, whereby the said steam outlet nozzle is adapted to direct asteam jet into said mixing chamber wherein a superfine mist-air mixtureis formed by the steam and entering ambient air, a venturi means at theopposite end of the mixing chamber for continuously aspirating themixture for delivery to a breathing device, the said venturi meanscomprising a venturi chamber having side walls and first and secondends, a venturi inlet tube connected to said first end of said venturichamber and adapted to be connected to a source of pressurized gas, saidventuri chamber having a diameter greater than said tube, said inlettube leading into said venturi chamber at said first thereof and havinga discharge orifice, the said venturi chamber having an opening in aside wall thereof and communicating with the steam-air mixing chamberwhereby a mist-air mixture from the latter can be aspirated into saidventuri chamber and means for conveying the mist-air mixture to abreathing device, the improvement comprising; a threaded bore in theventuri chamber wall at a location adjacent the venturi tube orifice, astem having an outer threaded portion, an inner unthreaded portion, andan inner end, said stem being threaded through the bore with the innerstem portion extending beyond the venturi chamber wall into the venturichamber and through a projected flow path of the venturi tube orifice,the said inner end being adjacent the venturi tube orifice, wherebyrotational movement of the stem serves to move the inner stem endtranslationally to cover and uncover at least a substantial portion ofthe projected flow path from the venturi tube orifice, thereby varyingthe vacuum produced by the venturi, finger gripping means fastened tothe other portion of the stem beyond the venturi chamber for rotatingthe stem and stop means for limiting the rotation of the stem.
 2. Thevaporizer of claim 1, comprising in addition a port in said mist-airconveying means, a support carrying a volatile medicament extendingthrough said port into the mist-air conveying means, whereby medicationis released into said stream.
 3. In the vaporizer and improvement ofclaim 1 wherein the stop means limit the rotation of the stem tosubstantially one revolution.
 4. In the vaporizer and improvement ofclaim 3 wherein the stop means comprises a pin on the finger grippingmeans coacting with a boss on in the venturi chamber wall.